1. Field of Invention
The present invention relates to a method for combining a radio frequency (RF) module on a motherboard of a computer system. More particularly, the present invention relates to a method for forming an integrated structure of a RF module on a motherboard of a computer system.
2. Description of Related Art
Increasingly developed communication technology brings more kinds of systems which can be used as a communication platform. From the circuit-switch telegram and telephone system in the early days to the packet-switch information network system in the present days, all are communication systems. A computer is the most important data accessing platform in the information network; hence, a module used to access the network data is usually installed in conventional computers.
The method for accessing the network data can be divided into several steps, of which a preliminary step is fetching an analog signal. For example, the physical line of an Ethernet system is used to transmit the encoded electronic signal. Therefore, when a computer system is used to receive data by Ethernet, the analog electronic signal should first be received via an analog signal processing module, called a physical layer, and then be converted into a digital data for follow-up processing by the digital data processing circuit in the computer system. Similarly, when the computer system is used to transmit digital data via an Ethernet, the digital data should first be converted to an analog electronic signal by the analog signal processing module, and then the analog electronic signal can be transmitted in a physical line. An analog signal processing module is thus an essential component for the computer system with a data communication function.
The physical transmission of wireless local area network (WLAN) system, such as the communication standards IEEE 802.11 a/b/g/n, also transmits an analog signal, but an analog electric wave signal transmitted by air is substituted for the analog electronic signal transmitted by a physical line. The computer system still needs a wireless radio frequency (RF) module to process the analog electric wave signal.
The integrated design of system circuit is a trend in the circuit design nowadays, and components such as a video card, an audio card and a wired network card are often integrated into a motherboard of a computer system. But some problems result if the wireless RF module is integrated into the motherboard of a computer system; for example, the operation efficiency of the wireless RF module will be substantially degraded because the digital signal processed by other digital units on the motherboard easily interfere with the analog signal processed by the wireless RF module.
The wireless network unit comprising a wireless RF module and a digital signal processing module is completely formed on an interface card in the conventional method. The wireless network interface card is then connected to a motherboard of computer via a standard interface, such as mini peripheral component interconnect (PCI). There is an isolating mechanism needed between the wireless RF module and the digital signal processing module for preventing the interference from each other digital units. The above-mentioned method for forming the wireless network unit has some drawbacks, such as a higher cost and a larger volume. Because an additional isolating mechanism and a standard interface are needed when both the wireless RF module and the digital signal processing module are formed on the interface card, forming the wireless network unit is more expensive. Moreover, because the standard interface is needed, the volume of the wireless network unit is difficult to reduce, and this are disadvantageous for installing the wireless network unit in a miniature computer system.